This invention relates to satellite constellation architectures.
This invention relates particularly to constellation architectures which have multiple inclined orbit planes distributed around 360.degree. with the satellites asymmetrically spaced in the orbit planes and with the satellites populating only a portion of each orbital plane so as to leave an open space in each orbital plane.
The coverage of the earth surface provided by various patterns of satellites has been the subject of many studies.
The results of certain ones of such studies have been published in the following publications.
(1) Royal Aircraft Establishment, Technical Report 70211, November 1970 "Circular Orbit Patterns Providing Continuous Whole Earth Coverage" by J. G. Walker, available from NTIS (National Technical Information Service, U.S. Department of Commerce, Springfield, Va. 22161); PA1 (2) Royal Aircraft Establishment, Technical Report 77044, Mar. 24, 1977, "Continuous Whole-Earth Coverage by Circular-Orbit Satellite Patterns" by J. G. Walker, available from NTIS (National Technical Information Service, U.S. Department of Commerce, Springfield, Va. 22161); PA1 (3) Royal Aircraft Establishment, Technical Report 82116, December 1982, "Coverage Predictions and Selection Criteria for Satellite Constellations" by J. G. Walker, available from NTIS (National Technical Information Service, U.S. Department of Commerce, Springfield, Va. 22161); PA1 (4) "Satellite Patterns for Continuous Multiple Whole-Earth Coverage" by J. G. Walker, Space Department, Royal Aircraft Establishment, Farnborough, U. K., presented as a publication at the International Conference on Maritime and Aeronautical Satellite Communication and Navigation on Mar. 7-9, 1978 at The Institution of Electrical Engineers, Savoy Place, London WC2.
Each of the four publications listed above is incorporated by reference in this application.
My co-pending application Ser. No. 08/770,480 filed Dec. 20, 1996 and entitled "Wave Based Satellite Constellation" and assigned to the same assignee as the assignee of this application illustrates and describes a number of wave based satellite constellations, and said application Ser. No. 08/770,480 is incorporated by reference in this application.
Certain forms of constellation architectures are commonly referred to as Walker Rosettes architectures. The architectures have been given the name Walker Rosettes in reference to the originating designer of such constellations and because of the rose petal tip appearance of the intersecting orbit planes when the constellations are viewed from a polar perspective.
The Walker Rosettes constellation architectures have multiple inclined orbit planes distributed around 360.degree. and always have satellites symmetrically positioned and equally spaced in each of the orbit planes.
As will be described in more detail below, Walker Rosettes which have satellites symmetrically positioned and evenly spaced in each of the orbit planes can require a greater number of satellites to obtain single or odd levels of coverage of the earth surface than the asymmetric open rosette constellations architecture of the present invention for large constellations.
The prior art Walker Roseffes constellation architectures also have not provided space in the orbit planes for additional satellites for growth or as spares.